Cookie Frosting: Royal Icing Recipe That Hardens Glossy

Instructions:

1. Sift the confectioner’s sugar and cream of tartar (if using) into the bowl of your stand mixer. This prevents dreaded lumps.
2. In a separate small bowl, whisk the meringue powder and 1/2 cup warm water together until slightly frothy. Add the extract.
3. Pour the liquid mixture over the sifted sugar in the mixer bowl.
4. Start the mixer on low speed until the sugar is incorporated, then increase to medium-high speed. Beat for 5 to 7 minutes until the icing is bright white, glossy, and forms stiff peaks. This is the Piping Consistency.
5. Divide the stiff base icing into smaller bowls according to how many colors you plan to use. Keep the bowls immediately covered with damp kitchen paper or cling film.
6. Use a toothpick to gradually incorporate gel food coloring into each bowl. Mix gently until the desired shade is reached.
7. Take the portion intended for flooding (filling in large areas). Add water, 1 teaspoon at a time, stirring thoroughly after each addition.
8. Perform the Consistency Check (The 10-Second Rule): Drizzle a spoonful of the thin icing back into the bowl. The line should disappear completely and merge back into the icing surface in 8–12 seconds.
9. Transfer the thick Piping Icing into piping bags fitted with small tips. Transfer the Flooding Icing into squeeze bottles or larger piping bags.
10. Outline: Use the thick Piping Icing to create a border around the edge of the cooled cookie. Allow this outline to dry for 10-15 minutes (this acts as a 'dam').
11. Flood: Fill the outlined area with the thinner Flooding Icing, gently spreading it to the edges using a scribe tool or toothpick.
12. Drying: Allow the decorated cookies to dry completely on a flat surface, ideally overnight (minimum 4 hours). High humidity will significantly lengthen the drying time.